Pressure is mounting on Beijing to respond to a neo-Maoist campaign spreading throughout the country that aims to bring two of the Great Helmsman's most outspoken critics to trial.

Utopia (or wyzxsx.com), one of the mainland's leading neo-Maoist websites claims to have collected thousands of signatures calling for the 'public prosecution' of economist Mao Yushi and writer Xin Ziling , a retired People's Liberation Army officer, for their comments on China.

Supporters of the campaign are encouraged to lodge 'citizens' complaints' with local public security authorities. The most high-profile signature obtained so far is reportedly that of Liu Siqi, widow of Mao Anying, Mao's son who died during the Korean war. Fan Jinggang, who runs the Utopia site, said this was only the beginning, with a second phase due to start on June 15 when a citizens' complaint would be formally delivered to the National People's Congress, the mainland's parliament, and to the municipal legislature.

Fan did not say whether the campaign had any official backing, but said citizens had ways of exercising their rights and defending Chairman Mao Zedong was one of those constitutional rights.

What sparked the campaign was Mao Yushi's review of Xin's book on Mao Zedong, called The Fall of the Red Sun, that was published on the economics information website Caing.com last month.

The 5,000 character review - it can no longer be read on Caing.com, but it is widely available online - is a damning account of Mao Zedong's policies.

'He is not god, and he will be removed from the altar, divested of all the myth that used to shroud him and receive a just evaluation as an ordinary man,' Mao Yushi wrote.

Xin's book is not sold on the mainland but can be downloaded from some web services. It is mainly about the political campaigns of the 1950s, in which innocent intellectuals were often labelled 'rightists' and fell victim to political persecution.

Mao Yushi was not available for comment, but Xin said he believed the neo-Maoists were not just targeting Mao Yushi and himself.

Their primary aim, he said, was to overturn an alleged politburo decision, said to have been made in December but never publicised, to drop the use of 'Mao Zedong thought' in all future party documents.

Fan insists such a document does not exist, calling it a rumour that started in the Hong Kong-based Cheng Ming magazine. But Xin maintains that the order was made, regardless of whether neo-Maoists want to believe it.

Xin also said his accusers would not even accept a newly published Communist Party history that states Mao's Great Leap Forward programme resulted in 10 million deaths from starvation from 1959 to 1961.

With the nation's 2012 leadership shakeup approaching, the arguments of both sides are being seen as attempts to influence the transition.

Xin said any plans that the neo-Maoists had to influence the leadership would be unsuccessful.

But confidence is running high in the neo-Maoist camp with some using online forums to liken their campaign to the Cultural Revolution.

A message posted on Maoflag.net said the campaign 'is the first gunshot we are going to fire ... it is very important to win the first battle and the best time is now'.

Whether the two critics are ever tried for their opinions would be a challenge for the leadership, said Professor Hu Xingdou of the Beijing Institute of Technology. 'We'll see how they use reason and defend the bottom line of law.'